The present invention relates to a novel cyclic tetrapeptide and a process for preparing the same.
The cyclic tetrapeptide according to the present invention is a novel compound which is not described in any literature or the like.
In The Journal of Antibiotics, 36, 478-483 (1983), compounds having similar structures to that of the compound of the present invention are listed. However, such compounds are distinguished from the compound of the present invention by their amino acid components. Also, there is no report which describes that such compounds inhibit transformation of cells.
With respect to a substance capable of normalizing transformed morphology of cells, there are reports as follows:
Genistein (Hiroshi Ogawara et al, The Journal of Antibiotics, 39, 606-608 (1986))
Erbstatin (Hamao Umezawa et al, The Journal of Antibiotics, 39, 170-173 (1986))
Oxanosine (Itoh, S. et al, Cancer Research,
49(4), 996-1000 (1989))
It is an object of the present invention to provide a cyclic tetrapeptide having the formula (I): ##STR2## wherein n is 4 or 3. A further object of the present invention is to provide a process for preparing the cyclic tetrapeptide (I).
These and the other objects of the present invention will become apparent from the description hereinafter.